JPH04539A - Exclusive control system - Google Patents

Abstract

PURPOSE:To easily execute complex exclusive control by allowing a system side to inquire the lock control state of a shared resource to a data base and inform the inquired result to a user side when a shared resource lock control request is information from the user side to the system side. CONSTITUTION:Shared resources A, E are registered in a process 32 by the data base 10, a request for acquiring the resources A, E is informed from a process 36 to an exclusive control part 38 based upon an inquiring expression (X-1), which is registered in the data base 10. When access to the constitutional elements (d), (f) of the resources A, E is unnecessary, the lock release request of the elements (d), (f) is informed from the process 36 to the control part 38 based upon an inquiring expression (X - 2) which is registered in the data base 10. At the end of the process 36, the constitutional element whose lock is not released out of the constitutional elements of the resources A, E is informed to the control part 38 based upon an inquiring expression (X - 3), which is registered in the data base 10.

Description

Detailed Description of the Invention Field of Industrial Applications Conventional Technology Problems to be Solved by the Invention Means for Solving the Problems Effects of the Invention [W1 Required Points for a system in which resources are shared by multiple processes Regarding exclusive control methods, we aim to provide a method that makes it possible to easily perform complex exclusive control, and we have developed a means to store and manage the states in which shared resources are locked as a database, and a method for handling lock control requests for shared resources. Detailed Description of the Invention Means for inquiring into a database about the state of lock control regarding the requested shared resource; Means for notifying the requestor of the lock control of the result of the inquiry; and a means for performing the same according to the above.

[Industrial Application Field] The present invention relates to an exclusive control method for a system in which resources are shared by a plurality of processes.

In this type of system, the same resource is shared by multiple processes, so exclusive control is required to ensure consistency of resource contents.

[Prior Art] When a user needs to access a shared resource and a system is notified of a resource acquisition request, the system inquires about the lock control state of the requested resource.

The result of the inquiry is then notified from the system side to the user side. If the resource is not locked, the resource is locked on the user side.

This prevents other processes from accessing the resource, allowing the requesting user to monopolize the resource.

Thereafter, when access to the acquired resource is completed and the user side notifies the system side of a request to unlock the acquired resource, the system side unlocks the resource related to the request.

Therefore, the resource becomes accessible to other users.

In FIG. 7, the contents of the shared resources are explained, and in this example, a plurality of shared resources are acquired at once.

University information 20 in FIG. 7(A) includes faculty information 24, address information 26. OB of figure 7 (B) formed from teaching information 28
Information 22 consists of the name of each university and the names of their alumni.
It is formed from B name information 3o.

When the university information 20 and the OB information 22 of each university become necessary on the user side, a request for acquiring these resources is notified to the system side.

Here, university information 20 and alumni information 22 are acquired in order. First, university information 20 is acquired, then faculty information 24. Address information 26. The user recognizes that the professor information 28 is formed from the faculty information 24. A request to acquire each resource such as address information 26 and teaching information 28 is notified to the system side.

Furthermore, the user recognizes that the OB information 22 is formed from the 08 name information 30, and
A resource acquisition request is notified to the system side.

When the system notifies the user that the requested resource is not locked, the university information 20
and OB information 22 are locked by the user.

As a result, the university information 20 and the OB information 22 are accessed by the user who requested the acquisition.

Conclusion For example, faculty information 24. It is possible to combine the tables of address information 26, professor information 28, and name information 30 and extract necessary data from them.

After that, faculty information 24. Address information 26. Professor information 28,
08 The user side notifies the system side of a request to unlock a resource that is no longer required to be accessed in the name information 30. The system side releases the lock of the requested resource at any time.

[Problems to be Solved by the Invention] As described above, when a user uses a shared resource, it is necessary to manage resource lock acquisition and lock release.

Therefore, it is a great burden on the user to manage the information without making any errors.

Furthermore, since resource lock acquisition and lock release are described in separate locations in the source program, it is easy to overlook lock control.

The present invention has been made in view of the above-mentioned conventional circumstances, and
The purpose is to provide a method that makes it possible to easily perform complex exclusive control.

[Means for Solving the Problems] In order to achieve the above object, the system according to the present invention is configured as shown in FIG.

In the figure, means 12 stores and manages the lock control state of shared resources as a database 10.

Then, the means 14 accepts the shared resource lock control request, and the means 16 inquires of the database 10 about the requested shared resource lock control state.

Further, the means 18 notifies the lock control requester of the inquiry result.The lock control means 20 performs lock control according to the inquiry result.

[Operations] In the present invention, the lock control state of shared resources is compiled into a database (10).

Then, when a user side notifies the system side of a lock control request for a coexisting resource, the system side queries the database 10 about the state of lock control regarding the requested shared resource.

During this time, the system side notifies the user side who requested the lock control of the 1 matching result.

[Embodiments] Hereinafter, preferred embodiments of the system according to the present invention will be described based on the drawings.

An embodiment is described in FIG. 2, in which a process 32 (user side) registers the history of shared resources and their lock control states in the database 10 of the resource management unit 34.

Then, the shared resource acquisition request or release request by the process 36 is accepted by the exclusive control unit 38 of the resource management unit 34. The exclusive control unit 38 inquires of the database 10 about the lock control status of the requested common resource. .

The result of this inquiry is the process 34 that requested lock control.
Lock control is performed according to the result of the inquiry notified by the exclusive control unit 38.

Next, let us specifically explain the operation of this embodiment. Database Registration> Shared resource A and shared resource E are registered in the database 10 by the process 32, and the shared resource A is registered with the components C and C. Card formed from element d Shared resource E
is formed from component f and component g.

In FIG. 3, an inquiry formula for the 4k database 10 is explained, and a request to acquire shared resource A and shared resource E from process 36 is sent to query formula X-1 (X-1=A
The exclusive control unit 38 is notified by the UE).

When this request is notified, query expression X-1 is registered in the database 10 (see FIG. 4).

Further, when access to component d and component f becomes unnecessary during the progress of the process 36, a request for unlocking component d and component f is made using the query expression
-2 (X-2=d, f), the process 36 notifies the exclusive control unit 38, and the query expression X-2 is registered in the database 10 (see FIG. 4).

Furthermore, at the end of the process 36, among the components of the shared resource A and the shared resource E, the furnace components that are unlocked (~) are expressed by the query formula X-3 (X-3=X-1\X-2). The exclusive control unit 38 is notified and the card inquiry formula X-3 is registered in the database 10 (see FIG. 4).

<Lock Acquisition> When the process 36 notifies the exclusive control unit 38 of a resource acquisition request using inquiry formula A component is queried using query expression X-1 (step 501 in FIG. 5).

Thereby, the constituent elements forming the shared resource A.

Component C9 A list of the lock control states of component f and component g that form component d and shared resource E is provided from database 10 to exclusive control unit 38 as an inquiry result.

The result of this inquiry is notified to the process 36 that made the resource acquisition request.The exclusive control unit 38 determines whether each resource can be acquired depending on the lock control state of the components S, C1, D, F, and G. (Step 503 in Figure 5).

And, component s, component C9 component d, component f
, if resources can be acquired for all component g, then (
If YES in step 503 of FIG. 5), each of these components is locked by the exclusive control unit 38 (step 505 of FIG. 5).

Also, component 1, component C2, component d.

If either component f or g cannot acquire resources, the resource acquisition requesting process is notified of resource acquisition failure (step 503 in FIG. 5).

When the process 36 notifies the exclusive control unit 38 of a request to release the lock using the inquiry formula X-2, the exclusive control unit 38 does not accept the request.The database 10 is queried using the inquiry formula X-2. (Figure 6 Step 601)
.

As a result, the lock control states of the component d and the component f are provided from the database 10 to the exclusive control unit 38 as an inquiry result.

The result of this inquiry is notified to the process 36 that made the resource acquisition request.The exclusive control unit 38 determines whether or not the locks can be released for the component d and the component f.
Figure step 603).

Then, if both component d and component f can be unlocked (YE in step 603 in Figure 6).
S), these components are unlocked (FIG. 6, step 605).

Further, if either the component d or the component f cannot be unlocked, the process 36 that made the resource acquisition request is notified of the unlock failure (step 607 in FIG. 6).

Further, when the process 36 notifies the exclusive control unit 38 of a request for unlocking using the inquiry formula X-3, the exclusive control unit 38 does not accept the request.
is queried using query formula X-3.

As a result, the lock control status of the acquired component C1, component d, component f, and component g is queried. The lock control state of the element C2 component g is provided from the database 10 to the exclusive control unit 38 as an inquiry result.

The result of this inquiry is notified to the process 36 that made the resource acquisition request, and the exclusive control unit 3 determines whether or not the lock can be released for the component C9 and the component g.
It will be judged by 8.

If it is possible to release the locks on all of the components S, C1, and G, these components are unlocked.

Furthermore, if any of the components A, C2, and G cannot be unlocked, the process 36 that made the resource acquisition request is notified of the failure to unlock.

As explained above, according to this embodiment, the lock control states of the shared resource A and the shared resource E are stored and managed in the database 10. -2°X-3 can be requested.

Therefore, resources can be acquired and unlocked without specifying each component of shared resource A and shared resource E one by one, making it possible to easily perform complex exclusive control without error. The burden of memory management can be reduced.

Furthermore, since the lock control of the shared resource can be requested in the form of an inquiry, even if the components of the shared resource are changed, there is no need to modify the source program, which reduces the burden on the user.

[Effects of the Invention] As explained above, according to the present invention, the lock control state of a shared resource is stored and managed in a database, and lock control of a shared resource can be requested in a query format, so complex exclusive control can be performed. This can be done easily.

Furthermore, since lock control of shared resources can be requested in the form of an inquiry, there is no need to modify the source program.

34...0 Resource Management Department 36...process 38...Exclusive control unit

[Brief explanation of drawings]

Fig. 1 is an explanation of the principle of the invention; Fig. 2 is an explanation of an embodiment; Fig. 3 is an explanation of contents of an inquiry type; Fig. 4 is an explanation of registered contents of a database; Fig. 5 is a flowchart showing the operation of resource acquisition; FIG. 6 is a flowchart showing the action of unlocking, and FIGS. 7(A) and (B) are explanations A of the contents of shared resources. 10...Database 32...Process engineering 1st route 3rd figure 5th rec

Claims (1)

[Claims] The state in which shared resources are under lock control is determined by a database (
10) means (12) for storage management; means (14) for receiving a lock control request for a shared resource; means (16) for inquiring the database (10) about the state of lock control regarding the requested shared resource; A means of notifying the lock control requester of the results (
18); and means (20) for performing requested lock control according to an inquiry result.